1 exclude (a person) from a society, favour, common privileges, etc.; refuse to associate with.
2 (esp. in ancient Athens) banish (a powerful or unpopular citizen) for five or ten years by popular vote.
Derivatives:
ostracism n.
Etymology: Gk ostrakizo f. ostrakon shell, potsherd (used to write a name on in voting)
Useful english dictionary. 2012.